1. Field of the Invention
This invention relates to a device for transporting sheet materials, lifting same into position and positioning same to a desired location. The device is adapted to lean against a vertical surface and balanced to retain the sheet material against the vertical surface.
2. Prior Art Statement
It is known to provide a tripod base on casters which can pick up a panel from a location near a surface, transport the panel to a place of installation, lift the panel into place up to 4 meters with an additional extension, rotate the panel for positioning and shift the entire apparatus for placement. The board handling frame has a lip on one end and a pair of lift tabs on one edge. For instance, see models 755011 and 755010 available from Refina Ltd., Unit 7, Upton Industrial Estate, Factory Road, Poole, Dorset, BH16 5SL, UK. This device cannot transport a panel through an interior household rough-in door opening as the tripod legs of the device are spaced at least one meter apart and the device must be disassembled for transport. The lower cost model of the device is offered at £599, that is, between $900 and $1000 USD and therefore is quite expensive. The wheels of the device must be locked in position in order to retain the panel in an installation position. No means for guiding the panel in a defined path is provided. Therefore, there exists a great need for a panel transport, lift and positioning device comprising a lift carriage on a two-wheeled transport dolly that can transport a panel laterally through an interior household rough-in door opening, lift and/or position the panel against a vertical surface and retain the panel against the surface without secondary retaining operations. There is a need for a device which expertly guides the panel upwardly along a frame work. Additionally, a lower cost transport, lift and positioning device is needed for independent contractors and individual builders.
It is also known to provide an optional floor loader attachment with a separate winch that allows lifting a panel from four inches above a floor level up to the hooks on the drywall lift device wherein the drywall lift device is mounted to a tripod base. For instance, see Panellift® 439 available from Telpro Inc., 7251 South 42nd Street, Grand Forks, N. Dak. 58201. Though quite robust, this device also cannot transport a panel through an interior household rough-in door opening and is more expensive. With the optional device, the entire panel must be lifted free of the floor up to the four inch level. No means is provided to direct the lifting of the panel along a straight path. Therefore, there is a great need for a panel transport, lift and positioning device comprising a two-wheeled transport dolly with a lift carriage that can transport a panel laterally through an interior household rough-in door opening, lift and/or position the panel against a vertical surface and retain the panel against the surface without secondary retaining operations while allowing loading of the panel at the floor level by lifting one end of the panel to engage the lip of the lift carriage. There is a need for a device which guides the panel upwardly in a straight path along a frame work of the device. There is also still a need for a lower cost panel transport, lift and positioning device.
It is further known to provide a frame that carries a movable intermediate frame which in turn has a loading frame movably attached thereto. A cable winch lifts both frames to a desired height allowing for installation of panels on a vertical surface, a horizontal surface or at any angle therebetween. As the device is relatively narrow and is mounted on caster wheels, movement of the device with its load through a doorway is possible though clearance for rotating the board through the door opening is required. For instance, see the U.S. Pat. No. 3,305,219 issued on Feb. 21, 1967 to Frank Rhodes. The device lifts a panel from a floor level but must be raised in position above the transport wheels and locked in position prior to transport. Though the device is useful in raising panels along a vertical surface for placement thereupon, the multiple locking and unlocking operations require additional time and effort therefore increasing the time required for mounting a panel. Therefore there is a need for a simply constructed, low cost panel transport, lift and positioning device that can have a panel placed on a carrying lip at a floor level, transport the entire device with panel laterally through door, manually lean the panel against a vertical surface, raise and or move the panel into position. As the panel transport, lift and positioning device has a center of gravity forward of surface engaging rollers, the panel transport, lift and positioning device of this invention retains the panel against the vertical surface as the panel transport, lift and positioning device is biased toward the vertical surface.
A known panel lift device comprises a pair of rectangular posts joined together with upper and lower cross bars. The upper cross bar is mounted to extensible legs slidably mounted in the rectangular posts and has a centrally mounted pulley. A pair of small rollers are provided adjacent the bottom end of the rectangular posts. A panel lifter plate is slidably engaged with an outer surface of the rectangular posts and has an eye attached for a cable from a winch. A winch is mounted on a third leg disposed between the rectangular posts, the third leg angularly mounted to a midpoint cross bar. The winch operates to lift the lifter plate. Each of the legs is further provided with an extensible foot to level the device on a support surface. The device is adapted to move a panel from a storage location to a wall, lift the panel to the desired height and mount the panel to the wall, however the device cannot move the panel laterally along the wall. Additionally, there is no means to guide the panel in a straight path while elevating the panel above the support surface. For instance, see the U.S. Pat. No. 5,303,899 issued on Apr. 19, 1994 to Jerome C. Palya. The inventor hereof has found that the small rollers used for transporting the panel of the cited patent are unsuitable for movement on most support surfaces and therefore there is a need for a panel transport, lift and positioning device comprising a lift carriage on a two-wheeled transport dolly wherein the transport wheels are substantial in diameter. There is also a need for a device which easily and expertly guides the panel upwardly along a frame work of the transport, lift and positioning device. The need for a panel transport, lift and positioning device that is relatively low in cost and is provided with rollers for moving a panel laterally along a vertical surface is great.
Another known device, shown and described in U.S. Pat. No. 5,584,635 issued on Dec. 17, 1996 to Frank Stapelmann, comprises a tiltable frame for transporting, fitting and installing panels that is carried on a castered base. The frame has a plurality of roller balls positioned below the panel that can be mechanically lowered into contact with the support surface wherein a front set of casters is lifted free of the floor and wherein the frame and panel may be moved laterally on the balls and the rear set of casters. The panel is strapped to the framework. The panel may only be lifted a short distance by mechanically lowering the roller balls onto the surface as no other lifting mechanism is provided. The plate carrying the roller balls is adjustable at both ends for leveling the panel. Though the device and panel may be moved laterally, it has been found that it is difficult to initially move the panel directly laterally as the rear casters must first pivot on a vertical axis thus causing the device and panel to yaw at initial movement. Additionally, since there is no additional lifting provided, placement of construction panels above a floor level is not possible so there is still a need for a device which may easily and expertly guide a panel upwardly along a frame work of the transport, lift and positioning device to a greatly elevated position. Thus, the great need for a simply constructed panel transport, lift and positioning device comprising a two-wheeled transport dolly with a lift carriage still exists.
Finally, it is known to provide a base with four larger diameter wheels wherein the base supports a laterally movable and forwardly tiltable frame. The frame has a lower lip for receiving the bottom edge of a door to be carried and a strap at its upper end for fixing the door to the tiltable frame. The movable frame carrying the panel may be shifted laterally relative to the base as the movable frame is mounted on a plurality of rollers. A lever, disposed between side edge members of the movable frame, is pivotally mounted on the base to laterally move the tiltable frame on the rollers. A minor vertical adjustment is provided on each side edge of the tiltable frame wherein a screw thread actuated by a hand crank is used to lower a roller against the support surface to raise the associated side edge of the tiltable frame. For instance, see the U.S. Pat. No. 6,241,447 B1 issued on Jun. 5, 2001 to James E. Echternacht. The rollers associated with the side edges of the tiltable frame are on axles parallel to the axle of the larger transport wheels and thus may not be used to move the door laterally. Additionally, lateral movement is limited as the rollers of the movable frame are limited to the width of an upper sill of the frame as well as the distance of throw of the lever between the side edges. Finally, the door must be strapped to the tiltable frame for transport and positioning. Therefore, the need still exists for a panel transport, lift and positioning device comprising a lift carriage on a two-wheeled transport dolly that can transport a panel laterally through an interior household rough-in door opening, lift and/or position the panel against a vertical surface, move the panel along the vertical surface by laterally shifting the panel transport, lift and positioning device on movement rollers associated with a lower edge of the device and retain the panel against the surface without secondary retaining devices. There is also a need for a device which easily and expertly guides the panel upwardly along a frame work of the transport, lift and positioning device.